1. Field of the Invention
This invention relates to integrated circuit (IC) amplifiers useful as buffers. More particularly, this invention relates to circuits employ transconductance generators and arranged to provide wide bandwidth operation with excellent pulse fidelity and low distortion.
2. Description of the Prior Art
Transconductance is the ratio of the output current of a device to its applied input voltage, and often is designated g.sub.m (the inverse of resistance). Devices of this sort are used in many different kinds of applications. For example, variable transconductance devices are extensively used in analog multipliers, and also in specialized analog computing circuits such as shown for example in U.S. Pat. Nos. 4,475,169 and 4,476,538 (Gilbert). Cross-coupled quad circuits also have been known for some time, and have been used as transconductance amplifiers as shown in Gosser Patent No. 4,970,470.
Buffer amplifiers available in the prior art have had significant performance limitations, particularly with regard to bandwidth and both a-c and d-c gain precision. It is a principal purpose of this invention to provide amplifier circuitry in the form of a transconductance generator having important advantageous characteristics overcoming such limitations in the prior art.